DAQ 6364 gives a spike in its AO when it will be measured

[Hossein128]

Dear college,

One of our customer has a problem with its DAQ6364. When he tries to measure the differential output in Matlab, there will be any problem but when he uses a Oscilloscope then he will see the spikes before the start point in his measuring. See the attachment.

Could you please inform me what the reason could be?

Thanks.

Kind regards,

Hossein

[Che_T.]

Hi Hossein,

To make sure that I understand you correctly, you're outputting on channel AO0.  When you measure it with the 6343 AI0, you don't see any spikes.  But, when you measure it with your oscilloscope, you see a 70mV spike.  Is this correct?

What oscilloscope are you using to measure this?  

[Hossein128]

Hi,

Thanks for your reply. I asked your question from my customer en he mentioned that he uses Tektronix DPO 4032 oscilloscope.
For more info about the issue I have to say that he measures the signal from his 6343 with Matlab and he will get the first result in the attachment which is in my last post. When he tries to use the oscilloscope he gets that spike which has influence on his sensors and that is why he cannot accept that. However this spike happened before the start point of measurement.

He already tried to use an external Low Pass filter with no success.
Do you have any suggestion beside this?

Thanks,

Hossein

[Hossein128]

Hi,

Could you give me more info about my question? My customer is waiting and unfortunately I cannot find the correct answer.

That would be very nice to hear from you very soon.

Thanks,

Hossein

[Hossein128]

Hi,

Could you please let me know why you didn't answer me last week?

I'm waiting for and hope to hear it very soon from you.

Thanks,

Regards,

Hossein